General EFIS and A320-specific questions

[Check Airman]

Hi all,



2 questions if you would



1- we’re usually taught that when changing a value (not mode) on the FCU/MCP, to verify that the new value is reflected on the PFD, and not just the FCU. Has anyone ever seen a situation where the PFD and FCU values are different?



2- A320 specific- When aligning the IRU’s, some people do 1-2-3, and others do 1-3-2. Is there any system-related reason that the order should matter? I remember this being discussed at one point, but I couldn’t find the thread.

Thanks for the replies.

[FlyingStone]

Been a while since I flew the Airbus, but:

It's probably policy on any modern aircraft that you don't rely on what MCP/FCU is showing (button lights, values), but rather on what your PFD/FMA/ND are showing. If there was a wiring or some sort of connection problem between MCP/FCU and other parts of avionics, the selected value/mode could potentially not be transmitted to other computers. Never seen it for real, but better safe than sorry.
I believe 1-2-3 is so you remember their positions, should you ever need to switch them off in flight, as 3 is in between 1 and 2 as I remember.

[Flap40]

1. Yes but probably less than 5 occasions over 20 years on F100 and 737. Most usually it's the selected Altitude that will show 100ft difference between the window and the screen.

2. I've not flown the 'bus so no comment.

[Capt Pit Bull]

Can’t comment on the bus but on the boeing you can’t deduce the state of the modes by looking at the MCP!

You can see what is deselectable, that does’t give you the complete picture.

e.g.
in alt hold, the mcp button might NOT be illuminated.
an illuminated VORLOC button could be armed not engaged.
an Illuminated AP button isn’t necessarily engaged (e.g early part of intended 2 channel approach)

This is why you look at the FMA not the MCP

how the **** do people not understand this? Why is the question even being asked?

**** training, that’s why.

this industry need to stoo cutting corners and pull its head out of its arse.

FFS. Somebody shoot me.

[Qwark]

1. For the Airbus its not a check that FCU and PFD/ND target values are the same, more to verify that the target has engaged. i.e When in NaV mode you can select a heading value, but if you dont pull to engage it, then NAV mode remains. The FCU only tells half the story. PFD and ND tell the full story!

2. Dont think there is any policy surrounding IRS order to align. I was originally training 1-2-3 sequence with the theory being when you have to switch one in-flight you are more likely to choose the correct one. “So is just a technique”.

[PilotLZ]

I can second the previous comments on number 2. In one company manual I have even seen it put straight - "the sequence shall be 1-2-3 to maintain awareness of switch location". Although, should you need to turn off an ADIRU in flight, you're not to do so without cross-confirmation from the other pilot as it is a non-reversible action.

[KayPam]

Hi all,



2 questions if you would



1- we’re usually taught that when changing a value (not mode) on the FCU/MCP, to verify that the new value is reflected on the PFD, and not just the FCU. Has anyone ever seen a situation where the PFD and FCU values are different?

2- A320 specific- When aligning the IRU’s, some people do 1-2-3, and others do 1-3-2. Is there any system-related reason that the order should matter? I remember this being discussed at one point, but I couldn’t find the thread.

Thanks for the replies.
The PFD and FCU values can be different in a case that is not exactly what you expect : when the pilot mistakes one knob for the other. Turn left heading 230 can soon turn into changing speed to 230kt. Checking on the PFD helps catching and avoiding this mistake.

The order does not matter but it helps pilots remember that 3 is in the middle, to do 1 2 3 instead of 1 3 2 which is more natural.

**** training, that’s why.

Don't judge people or schools so fast..
Everywhere I've been, people have taught me the "act and check" principle or whatever it's called in English.

[Check Airman]

Thanks for the feedback so far guys.

To be clear, I’m not talking about mode awareness on the FMA. I’m only talking about the actual numbers. Eg have you ever put 300 in the speed window and had anything but 300 get bugged on the PFD?

[Fursty Ferret]

To be clear, I’m not talking about mode awareness on the FMA. I’m only talking about the actual numbers. Eg have you ever put 300 in the speed window and had anything but 300 get bugged on the PFD?

Yes. An SDAC fault can result in more or less random values being sent from the FCU to the FMGCs - both values and modes.

[vilas]

Hi all,



2 questions if you would



1- we’re usually taught that when changing a value (not mode) on the FCU/MCP, to verify that the new value is reflected on the PFD, and not just the FCU. Has anyone ever seen a situation where the PFD and FCU values are different?
2- A320 specific- When aligning the IRU’s, some people do 1-2-3, and others do 1-3-2. Is there any system-related reason that the order should matter? I remember this being discussed at one point, but I couldn’t find the thread.

Thanks for the replies.
As we know Airbus knobs or anything like gear or flaps even are electrical switches not mechanically connected. So it's not enough you put switch on but also need to be check that it has worked e.g. Bulb or fan in a room has started. The chance of getting a different value on FMA/PFD may not be there but the particular switch not affecting the change at all is there. Like pulling ALT is a desire expressed but it needs to be confirmed that the aircraft is doing what was asked. Sometimes you need to pull again.
As far as IRU being switched 1,2, 3 has no systemic issue but to drive it into subconscious the fact that IR3 is in the middle. Because otherwise when dealing with abnormals you may swich off IR3 instead of IR2.

[Check Airman]

Thanks guys. My airline has an odd sop where we change altitudes by putting the new altitude into the FCU, and pointing to the FCU. The last operator had us point to the PFD, which made more sense.

I’m told that this is the newest, best way of doing things, so I guess I’ll point to the FCU :rolleyes:

[PilotLZ]

Strange policy. In the first place, I couldn't quite understand if you're required to physically point at the FCU altitude window while reading it out. If yes, why? This sort of parasitic movements are generally discouraged (except for the limited cases of pointing at a control for cross-confirmation purposes) as they increase the risk of something being pushed or moved inadvertently. Also, the idea behind reading the values off the FCU instead of the PFD remains a mystery to me. The FCU is merely an input interface to the autoflight system, just as the mouse or the keyboard to a computer. If it's not communicating properly with the rest of the autoflight system, checking the readings on the PFD is your safeguard against letting the loss of integrity slip unnoticed. I'm all in favour of advancement in workplace practices, but some "new" things literally sound like reinventing the hot water.

[Check Airman]

We’re experts in strange policies. If I made the rules, I’d just put the airline logo on the Airbus SOP and settle it at that- even with the FMA call outs, which I dislike.

Unfortunately I don’t get to write the SOP, so I’ll just adhere to them until they change with the next management shuffle.

[Max Angle]

until they change with the next management shuffle.
Which they will as surely as the sun rises!!

[Uplinker]

Hi C.A.

1. In 13 years of flying A320/321/330; No.

2. As several have said, to make it a subconscious motor program so your brain knows which ADIRU is which.

On my previous types: Dash 8's and BAe146's, if we changed the Alt, we would keep a finger on the FCU readout until the other pilot acknowledged the new value. Airbus SOPs require a vocalisation and acknowledgement of any change or new value seen on the PFD, so this covers the cross-check requirement. Some on other threads have said their company SOPs for flying Airbus do not mandate this vocalisation. I would say to those companies beware !

[PilotLZ]

We’re experts in strange policies. If I made the rules, I’d just put the airline logo on the Airbus SOP and settle it at that- even with the FMA call outs, which I dislike.

Unfortunately I don’t get to write the SOP, so I’ll just adhere to them until they change with the next management shuffle.
Golden words. I would have done the absolute same. Why does anyone have to pretend that they know better than the manufacturer how to fly the aircraft? Those were the procedures it was tested and certified with, how come that they are suddenly deemed inadequate and unfit for purpose (which is exactly what the heavy "customization" of SOPs suggests)?

[Check Airman]

Hi C.A.

1. In 13 years of flying A320/321/330; No.

2. As several have said, to make it a subconscious motor program so your brain knows which ADIRU is which.

On my previous types: Dash 8's and BAe146's, if we changed the Alt, we would keep a finger on the FCU readout until the other pilot acknowledged the new value. Airbus SOPs require a vocalisation and acknowledgement of any change or new value seen on the PFD, so this covers the cross-check requirement. Some on other threads have said their company SOPs for flying Airbus do not mandate this vocalisation. I would say to those companies beware !

I like the finger on the FCU technique. I’ve never had to vocalise anything but altitudes though. I’ve seen a few YouTube videos and it seems tiring- to be generous. Still, I’d be more comfortable following Airbus SOP to the letter than some random guy’s technique.

[Check Airman]

Golden words. I would have done the absolute same. Why does anyone have to pretend that they know better than the manufacturer how to fly the aircraft? Those were the procedures it was tested and certified with, how come that they are suddenly deemed inadequate and unfit for purpose (which is exactly what the heavy "customization" of SOPs suggests)?

Because “we’ve always done it this way”. :ugh:

[FlyingStone]

Why does anyone have to pretend that they know better than the manufacturer how to fly the aircraft? Those were the procedures it was tested and certified with, how come that they are suddenly deemed inadequate and unfit for purpose (which is exactly what the heavy "customization" of SOPs suggests)?

Sticking to Mr. Boeing/Airbus SOP has a distinct disadvantage - it means the airline's SMS has nearly zero input into it, and the input it might have, will have an enormous latency between the line events and the implementation of the SOP change that seeks to eliminate similar events from occuring.

Manufacturers cannot predict every single operational environment in the world, and these will vary a lot between airlines - e.g. requency changes over Africa, where all frequencies have a single decimal number and occur once every hour pose less risk of dialing the wrong frequency, getting into PLOC and perhaps even getting intercepted than operating in Maastricht/Rhein area in EU, where you have 8.33 frequencies, and changes less than 5 mins apart.

Similarly, pointing to MCP/FCU might seem silly to somebody who operates in airspece, where you get five level changes in the entire flight, but it might - possibly - make a small bit of sense when you operate 4 or 6 sector days into London TMA, FRA, etc., where you often get 20 level changes on the way up and 20 on the way down.

[Check Airman]

To be clear, things like you're describing are ok to tweak a bit, in my opinion. My airline however, has a tendency to change more consequential procedures- like flight control checks, go around call-outs and splitting of duties during critical phases. That kind of stuff, you shouldn't mess with, no matter how well it worked on the DC3.

The SMS folks should absolutely have a say in the SOPs for a given operation. As you said, different theatres present different challenges, but their recommendations shouldn't go contrary to the manufacturer's SOP.

[sonicbum]

Sticking to Mr. Boeing/Airbus SOP has a distinct disadvantage - it means the airline's SMS has nearly zero input into it, and the input it might have, will have an enormous latency between the line events and the implementation of the SOP change that seeks to eliminate similar events from occuring.

Manufacturers cannot predict every single operational environment in the world, and these will vary a lot between airlines - e.g. requency changes over Africa, where all frequencies have a single decimal number and occur once every hour pose less risk of dialing the wrong frequency, getting into PLOC and perhaps even getting intercepted than operating in Maastricht/Rhein area in EU, where you have 8.33 frequencies, and changes less than 5 mins apart.

Similarly, pointing to MCP/FCU might seem silly to somebody who operates in airspece, where you get five level changes in the entire flight, but it might - possibly - make a small bit of sense when you operate 4 or 6 sector days into London TMA, FRA, etc., where you often get 20 level changes on the way up and 20 on the way down.

It does not make any sense to point the altitude on the FCU ; Airbus callout is FL XXX blue (or magenta in case). Pointing the FCU is only half of the story and in case of an alt constraint lower than the FCU altitude it is actually misleading. What the airplane will do is only dictated by the FMA, all other data is almost useless.

[vilas]

There's a safer and simpler way. Inform the manufacturer about your proposed changes. Because apart from the design philosophy and software and hardware access the manufacture has a global customer reach and incidents. So if you want to change something in Argentina that may have been already done in Korea and ended in a screw up. Armed with FCOM, FCTM no one is in a position to make their own procedures. There's famous incident of Jetstar Australia and two other Airlines changing FMA call on GA to only after gear up. The captains stopped short of TOGA and waited for gear up to check the FMA. Copilot waited for positive climb to put gear up. The aircraft remained in approach and worst case it came down to 14feet before they pulled up. All returned to previous procedure. TOGA first FMA to confirm transition to GA then everything else.

[Check Airman]

It does not make any sense to point the altitude on the FCU ; Airbus callout is FL XXX blue (or magenta in case). Pointing the FCU is only half of the story and in case of an alt constraint lower than the FCU altitude it is actually misleading. What the airplane will do is only dictated by the FMA, all other data is almost useless.

The case with altitude constraints is the only case where I’ve seen the PFD not match the FCU (by design).

This situation is where I actually find it useful to point to the FCU. ATC clears you to 6000, and the FCU reflects that clearance limit, even though the PFD shows 12,100 in pink.

[WhatShortage]

Can’t comment on the bus but on the boeing you can’t deduce the state of the modes by looking at the MCP!

You can see what is deselectable, that does’t give you the complete picture.

e.g.
in alt hold, the mcp button might NOT be illuminated.
an illuminated VORLOC button could be armed not engaged.
an Illuminated AP button isn’t necessarily engaged (e.g early part of intended 2 channel approach)

This is why you look at the FMA not the MCP

how the **** do people not understand this? Why is the question even being asked?

**** training, that’s why.

this industry need to stoo cutting corners and pull its head out of its arse.

FFS. Somebody shoot me.
Relax pitbull, he is probably ( most likely) asking about the bus, reason for that his second question. And you wonder, why is that guy asking that? Maybe because he had a captain just like you in training that such kind of question would immediately rise his attention and not in a good way, could that be the reason?.. Maybe??? Just saying.

[sonicbum]

The case with altitude constraints is the only case where I’ve seen the PFD not match the FCU (by design).

This situation is where I actually find it useful to point to the FCU. ATC clears you to 6000, and the FCU reflects that clearance limit, even though the PFD shows 12,100 in pink.

You mean magenta I guess.

Depends a lot on airlines SOPs then. We never set anything lower (higher) than the active constraints, I.e. cleared down to 6000 ft via STAR we set the different step down constraints on the FCU, but yes technically it is perfectly fine to just set your final altitude provided you are in DES or CLB all the time.
If your policy is the latter, then I see the point of your comment.

[Check Airman]

You mean magenta I guess.

Depends a lot on airlines SOPs then. We never set anything lower (higher) than the active constraints, I.e. cleared down to 6000 ft via STAR we set the different step down constraints on the FCU, but yes technically it is perfectly fine to just set your final altitude provided you are in DES or CLB all the time.
If your policy is the latter, then I see the point of your comment.

yes. Magenta.

I have to ask. Why? Assuming you fly a Boeing/Airbus, what’s the benefit, and how do you handle soft constraints (eg 21,000-23,000)?

[Tail-take-off]

Hi all,




1- we’re usually taught that when changing a value (not mode) on the FCU/MCP, to verify that the new value is reflected on the PFD, and not just the FCU. Has anyone ever seen a situation where the PFD and FCU values are different?



I had this just the other day. While Changing the BARO QNH setting with the selector on the FCU, the value in the FCU window didn’t change but the value on the PFD did (including a corresponding change in altitude indicated).

A basic Airbus principle is to look for the output rather than rely on the input. If you try to switch your kitchen light on you check that the bulb has illuminated rather than relying on the switch position alone.

[sonicbum]

yes. Magenta.

I have to ask. Why? Assuming you fly a Boeing/Airbus, what’s the benefit, and how do you handle soft constraints (eg 21,000-23,000)?

As many operators, we also had a few level busts over the years, because of crew selecting the final cleared altitude on SID/STARS with constraints in the middle and for some reason getting out of CLB/DES and here you go, you get a level bust. We basically write down the final cleared altitude on PM MCDU (eg. descend via STAR 3000 ft) and select step by step the different altitudes on the STAR (5000 ft, 4000ft, etc..).

I am not a big fan of the above procedure, as we were discussing above “know your FMA at all times” should be the priority but as we know our business is driven by internal and external statistics.

[Check Airman]

I had this just the other day. While Changing the BARO QNH setting with the selector on the FCU, the value in the FCU window didn’t change but the value on the PFD did (including a corresponding change in altitude indicated).


Interesting. How’d you fix it?

[Check Airman]

As many operators, we also had a few level busts over the years, because of crew selecting the final cleared altitude on SID/STARS with constraints in the middle and for some reason getting out of CLB/DES and here you go, you get a level bust. We basically write down the final cleared altitude on PM MCDU (eg. descend via STAR 3000 ft) and select step by step the different altitudes on the STAR (5000 ft, 4000ft, etc..).


That would not be fun going into LAX on the Hollywood STAR. Just about every fix has a constraint, but it’s pretty simple. You set the FCU to 12,000 for the bottom of the star, then you set the FAF altitude when cleared for the approach at ~ FL200. Easy as pie (when it all works :)). DES is a lovely thing.

Thanks for the insight though. There are as many ways to do it as there are operators.

[Tail-take-off]

Interesting. How’d you fix it?

7 minute FCU reset of both channels (we were on the ground).

[AerocatS2A]

As many operators, we also had a few level busts over the years, because of crew selecting the final cleared altitude on SID/STARS with constraints in the middle and for some reason getting out of CLB/DES and here you go, you get a level bust. We basically write down the final cleared altitude on PM MCDU (eg. descend via STAR 3000 ft) and select step by step the different altitudes on the STAR (5000 ft, 4000ft, etc..).

I am not a big fan of the above procedure, as we were discussing above “know your FMA at all times” should be the priority but as we know our business is driven by internal and external statistics.

So what happens if the PM needs the MCDU for something else? I'm also curious if your company just ended up replacing constraint busts with final clearance limit busts. I guess not, particularly if you tend to get cleared lower before reaching the level.

[Black Pudding]

I flew with a guy who failed his upgrade a few years ago and was hoping to be given another shot at it sometime in the future.

As we climbed out passing transition altitude, as with SOPs I said “Set Standard” and although he did the action, his side remained on the QNH. He then replied as with SOPs “Standard cross checked passing FL???” even though in front of him it was very clear he still had the QNH set.

[Roj approved]

Thanks for the feedback so far guys.

To be clear, I’m not talking about mode awareness on the FMA. I’m only talking about the actual numbers. Eg have you ever put 300 in the speed window and had anything but 300 get bugged on the PFD?

I’ve set 180° with the heading knob once and somehow the speed bug showed 180kts on the PFD😩😩 it’s worth checking.

On the E Jet, there are no lights or digits on the MCP/FCU. The only way to confirm you have set/selected anything is to check the PFD.

[compressor stall]

I’ve set 180° with the heading knob once and somehow the speed bug showed 180kts on the PFD😩😩 it’s worth checking.
PFD.

And that’s why you turn the FCU and read the PFD.

Amen

[sonicbum]

So what happens if the PM needs the MCDU for something else? I'm also curious if your company just ended up replacing constraint busts with final clearance limit busts. I guess not, particularly if you tend to get cleared lower before reaching the level.

The PM will then use the MCDU as needed.

Apparently the fleet office is quite happy with the statistics of this SOP. There have been in the past events where the crew mainly changed from DES to V/S and that lead to the troubles. The mitigation strategy was to prohibit the use of V/S when descending/climbing "via" a STAR/SID and the use of step FCU altitude selections. My bet is that the latter will be removed soon as, again, it does not make sense if things are done properly from the beginning.

[vilas]

The PM will then use the MCDU as needed.

Apparently the fleet office is quite happy with the statistics of this SOP. There have been in the past events where the crew mainly changed from DES to V/S and that lead to the troubles. The mitigation strategy was to prohibit the use of V/S when descending/climbing "via" a STAR/SID and the use of step FCU altitude selections. My bet is that the latter will be removed soon as, again, it does not make sense if things are done properly from the beginning.
It may have happened due to incomplete understanding of DES mode and constraint compliance. Easier to explain that than device more complicated solution.

[FlightDetent]

If the vertical profile guidance before FAF/P was not such crap, perhaps people would be inclined to using the DES mode without intervening all the time?

But it is not.

[sonicbum]

It may have happened due to incomplete understanding of DES mode and constraint compliance. Easier to explain that than device more complicated solution.

Nah, people with over 10k hours on type, just trying to be smarter and doing it "better" than the system. Then a distraction comes in, and here you go.
Unfortunately from a trainer's point of view the solution is always the same : training !
From a Ops/safety point of view it's training AND something else to teach the remaining 99% of the pilots population not to be naughty.

[Check Airman]

The PM will then use the MCDU as needed.

Apparently the fleet office is quite happy with the statistics of this SOP. There have been in the past events where the crew mainly changed from DES to V/S and that lead to the troubles. The mitigation strategy was to prohibit the use of V/S when descending/climbing "via" a STAR/SID and the use of step FCU altitude selections. My bet is that the latter will be removed soon as, again, it does not make sense if things are done properly from the beginning.

Man. I sure hope nobody from my airline management is reading this. This is exactly the sort of stuff they come up with that leaves us wondering why we’re flying the thing like it’s a 707.

[Check Airman]

If the vertical profile guidance before FAF/P was not such crap, perhaps people would be inclined to using the DES mode without intervening all the time?

But it is not.

I hear even the 787 guys aren’t impressed with the VNAV. That’s a good thing right? It means our jobs are still safe. Right?

[pineteam]

Thanks guys. My airline has an odd sop where we change altitudes by putting the new altitude into the FCU, and pointing to the FCU. The last operator had us point to the PFD, which made more sense.

I’m told that this is the newest, best way of doing things, so I guess I’ll point to the FCU :rolleyes:

We have the same procedure. it's actually an AIRBUS, ICAO and IATA recommended procedure. The aim is to confirm the selected altitude before engaging the climb/ descend mode to prevent altitude burst. If anyone interested I can Email the Airbus document.

Edit: Found the one from Airbus online: https://www.skybrary.aero/bookshelf/books/194.pdf

[FlightDetent]

I am quite convinced that when saying "altitude window" in the FOBN, Airbus is just copying the regulatory guidance verbatim.

What they mean, and define in the generic SOP of FCOM, is to set the value silently and then verbalise the readout from FMA - in their particular installation.

[pineteam]

The procedure is pretty clear in our SOP; It's really pointing to the FCU first. it might look ridiculous at first but it's actually not that bad. I guess this procedure is more adequate for operators flying daily into China when you get a lot of step climbs and step descents in meters where we need to do the conversion all the time in feet. Altitude burst is a serious event in that part of the world.

[Citation2]

Airbus recommends to select the FCU altitude to the next constraint altitude during climb

Quote from FCOM system related procedure / climb / monitoring the climb phase :

RECOMMENDATION:To ensure that you will not miss the next constraint, it is recommended to select the FCU altitude to the next constraint as described above.